Android EventLog含义

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一. 概述

在调试分析Android的过程中，比较常用的地查看EventLog，非常简洁明了地展现当前Activity各种状态，当然不至于此，比如还有window的信息。那么本文就列举以下am相关的tags含义。

本文涉及的源码类有EventLog.java, EventLogTags.java，另外tags格式的定义位于文件/system/etc/event-log-tags。

如果在终端输入：

1	logcat -b events

那么会输出大量类似这样的信息：

06-01 13:44:55.518 7361 8289 I am_create_service: [0,111484394,.StatService,10094,7769]

06-01 13:44:55.540 7361 8343 I am_proc_bound: [0,3976,com.android.providers.calendar]

06-01 13:44:55.599 7361 8033 I am_create_service: [0,61349752,.UpdateService,10034,1351]

06-01 13:44:55.625 7361 7774 I am_destroy_service: [0,61349752,1351]

...

通过字面意思，就能得到不少信息量，比如am_create_service，创建service，但是后面括号中内容的具体含义，其实有很高的价值。接下来通过一张表格来展示含义。

二. EventLog

2.1 AM

Num	TagName	格式	功能
30001	am_finish_activity	User,Token,TaskID,ComponentName,Reason
30002	am_task_to_front	User,Task
30003	am_new_intent	User,Token,TaskID,ComponentName,Action,MIMEType,URI,Flags
30004	am_create_task	User ,Task ID
30005	am_create_activity	User ,Token ,TaskID ,ComponentName,Action,MIMEType,URI,Flags
30006	am_restart_activity	User ,Token ,TaskID,ComponentName
30007	am_resume_activity	User ,Token ,TaskID,ComponentName
30008	am_anr	User ,pid ,Package Name,Flags ,reason	ANR
30009	am_activity_launch_time	User ,Token ,ComponentName,time
30010	am_proc_bound	User ,PID ,ProcessName
30011	am_proc_died	User ,PID ,ProcessName
30012	am_failed_to_pause	User ,Token ,Wanting to pause,Currently pausing
30013	am_pause_activity	User ,Token ,ComponentName
30014	am_proc_start	User ,PID ,UID ,ProcessName,Type,Component
30015	am_proc_bad	User ,UID ,ProcessName
30016	am_proc_good	User ,UID ,ProcessName
30017	am_low_memory	NumProcesses	Lru
30018	am_destroy_activity	User ,Token ,TaskID,ComponentName,Reason
30019	am_relaunch_resume_activity	User ,Token ,TaskID,ComponentName
30020	am_relaunch_activity	User ,Token ,TaskID,ComponentName
30021	am_on_paused_called	User ,ComponentName
30022	am_on_resume_called	User ,ComponentName
30023	am_kill	User ,PID ,ProcessName,OomAdj ,Reason	杀进程
30024	am_broadcast_discard_filter	User ,Broadcast ,Action,ReceiverNumber,BroadcastFilter
30025	am_broadcast_discard_app	User ,Broadcast ,Action,ReceiverNumber,App
30030	am_create_service	User ,ServiceRecord ,Name,UID ,PID
30031	am_destroy_service	User ,ServiceRecord ,PID
30032	am_process_crashed_too_much	User ,Name,PID
30033	am_drop_process	PID
30034	am_service_crashed_too_much	User ,Crash Count,ComponentName,PID
30035	am_schedule_service_restart	User ,ComponentName,Time
30036	am_provider_lost_process	User ,Package Name,UID ,Name
30037	am_process_start_timeout	User ,PID ,UID ,ProcessName	timeout
30039	am_crash	User ,PID ,ProcessName,Flags ,Exception,Message,File,Line	Crash
30040	am_wtf	User ,PID ,ProcessName,Flags ,Tag,Message	Wtf
30041	am_switch_user	id
30042	am_activity_fully_drawn_time	User ,Token ,ComponentName,time
30043	am_focused_activity	User ,ComponentName
30044	am_home_stack_moved	User ,To Front ,Top Stack Id ,Focused Stack Id ,Reason
30045	am_pre_boot	User ,Package
30046	am_meminfo	Cached,Free,Zram,Kernel,Native	内存
30047	am_pss	Pid, UID, ProcessName, Pss, Uss	进程

下面列举tag可能使用的部分场景：

am_low_memory：位于AMS.killAllBackgroundProcesses或者AMS.appDiedLocked，记录当前Lru进程队列长度。
am_pss：位于AMS.applyOomAdjLocked或者AMS.requestPssLocked
am_meminfo：位于AMS.dumpApplicationMemoryUsage
am_proc_start:位于AMS.startProcessLocked，启动进程
am_proc_bound:位于AMS.attachApplicationLocked
am_kill: 位于ProcessRecord.kill，杀掉进程
am_anr: 位于AMS.appNotResponding
am_crash:位于AMS.handleApplicationCrashInner
am_wtf:位于AMS.handleApplicationWtf
am_activity_launch_time：位于ActivityRecord.reportLaunchTimeLocked()，后面两个参数分别是thisTime和 totalTime
am_activity_fully_drawn_time:位于ActivityRecord.reportFullyDrawnLocked, 后面两个参数分别是thisTime和 totalTime
am_broadcast_discard_filter:位于BroadcastQueue.logBroadcastReceiverDiscardLocked
am_broadcast_discard_app:位于BroadcastQueue.logBroadcastReceiverDiscardLocked

2.2 Power

Num	TagName	格式	功能
2722	battery_level	level, voltage, temperature
2723	battery_status	status,health,present,plugged,technology
2730	battery_discharge	duration, minLevel,maxLevel
2724	power_sleep_requested	wakeLocksCleared	唤醒锁数量
2725	power_screen_broadcast_send	wakelockCount
2726	power_screen_broadcast_done	on, broadcastDuration, wakelockCount
2727	power_screen_broadcast_stop	which,wakelockCount	系统还没进入ready状态
2728	power_screen_state	offOrOn, becauseOfUser, totalTouchDownTime, touchCycles
2729	power_partial_wake_state	releasedorAcquired, tag

battery_level: [19,3660,352] //剩余电量19%, 电池电压3.66v, 电池温度35.2℃ power_screen_state: [0,3,0,0] // 灭屏状态(0), 屏幕超时(3). 当然还有其他设备管理策略(1),其他理由都为用户行为(2) power_screen_state: [1,0,0,0] // 亮屏状态(1),

下面列举tag可能使用的部分场景：

power_sleep_requested: 位于PMS.goToSleepNoUpdateLocked
power_screen_state:位于Notifer.handleEarlyInteractiveChange, handleLateInteractiveChange

2.3 Notification

|Num|TagName|格式|功能| |—|—|—|

三. EventLog完整语义分析

在源码EventLogTags.java中,有大量类似的定义,那么括号中数字是什么含义呢? (以进程启动为例)

1	30014 am_proc_start (User\|1\|5),(PID\|1\|5),(UID\|1\|5),(Process Name\|3),(Type\|3),(Component\|3)

格式:

1 2	(<name>\|data type[\|data unit]) (<名字>\|数据类型[\|数据单位])

数据类型:

1: int
2: long
3: string
4: list

数据类型中int和string用得最多.

数据单位:

1: Number of objects(对象个数)
2: Number of bytes(字节数)
3: Number of milliseconds(毫秒)
4: Number of allocations(分配个数)
5: Id
6: Percent(百分比)

实例解析:

1 2	am_proc_start (User\|1\|5),(PID\|1\|5),(UID\|1\|5),(Process Name\|3),(Type\|3),(Component\|3) am_proc_start: [0,9227,10002,com.android.browser,content provider,com.android.browser/.provider.BrowserProvider2]

含义 ==> 进程启动: pid=9227,uid=10002, 进程名=com.android.browser, 类型ContentProvider,相应组件=com.android.browser/.provider.BrowserProvider2

作者微博：@Gityuan

原文出处：Gityuan.com